Electric immersion heater assembly

ABSTRACT

An electric immersion heater assembly for hot water heating boilers provided in one form as a single phase circuit with a central conductive reinforcing rod that is utilized as one electrode and a ceramic body surrounding said rod with a resistance heating wire spirally wound upon said ceramic body and connected at its other end with a second electrode, said electrodes extending out of the heater at the unimmersed end and said immersed portion glazed with a non-conductive coating. A further embodiment includes a multi-phase circuit and in which the central core includes three reinforcing conductive electrodes that are Delta connected to a multiphase power line.

United States-Patent I Zeitlin et a1.

51 (3,707,618 51 Dec.26, 1972 [541 ELECTRIC IMMERSION HEATER ASSEMBLY [72] Inventors: Edward J. Zeltlln, Purdys; Lee Leighton, Mohegan Lake, both of [52] US. CL; ..2l9/336, 219/536, 219/546 [51] Int. Cl. .....ll0$b 1/00 [58] Field 01 Search ..2l9/335, 336, 337, 316, 318,

9/1948 Green,J r...., "219/335 10/1965 Steenbergen ..2l9/336X Primary Examiner-C. L. Albritton Attorney-Howard T. Jeandron [57] ABSTRACT An electric immersion heater assembly for hot water heating boilers provided in one fonn as asingle phase circuit with a central conductive reinforcing rod that is utilized as one electrode and a ceramic body surrounding said rod with a resistance heating wire spirally wound upon said ceramic body and connected at its other end with a second electrode, said electrodes extending out of the heater at the unimmersed end and said immersed portion glazed with a non-con- 29/6 ductive coating. A further embodiment includes a multi-phase circuit and in which the central core in- [56] References cued eludes three reinforcing conductive electrodes that are UNITED STATES PATENTS Delta connected to a multiphase power line. 1,743,577 1/1930 Smith ..2l9/335 5 Claims, 10 Drawing Figures PATENTED 05025 I972 SHEET 1 OF 2 INVENTORS EDWARD .1. ZEITL. 11v

BY LEJEH ra/v AGENT PATENTED C I972 3.707.618

sum 2 BF 2 /4A f M INVENTORS EDWARD J. 281 TLIN BY LEE LEJGHTUN 1 ELECTRIC IMMERSION HEATER ASSEMBLY non-conductive rod, said rod having a conductive center thatalsoreinforces the extended length of said rod, said rod glazed to be waterproof for insertion into a hot water heating boiler, saidrod mountable through an opening in said boiler end plate and clamped to said boiler end plate to retain said electric immersion heater assembly in an operative, sealed position in said boiler.

In use in the trade, heaters of this type are generally comprised of a central non-conductive core with the heating filament or resistance wire wrapped around the core and the completely wound heater extending to be immersed in the fluid of the tank for heating the water. Due to the length of the heater and the material (generally a vitreous non-conductor such as porcelain), there is a danger of the supporting core cracking or actually breaking under extreme stress. The boilers in which these heaters are mounted are shipped, generally by truck, to the job for installation. Many of them are handled roughly or dropped. This results in broken cores and defective heaters.

It is an object of this invention to provide an electric immersion heater'assembly that is. reinforced along its entire length to insure sufficient strength to the supporting core and prevent cracking or actual breaking of the unit after it is mounted in a boiler or tank.

It is a further object of this invention'to provide a singlejphase electric immersion heater assembly comprised of central steel reinforcing rods for strength, to which a ceramic covering is applied and a resistance wire heating element is spirally wound on the surface of said non-conductive covering and a protective vitreous glaze applied to completely cover said unit and make same completely waterproof so that the unit may be immersed' in a tank of liquid as the means of heating said liquid. 7

It is a further object of this invention to provide a multi-phase electric immersion heater assembly comprised of a plurality of central steel reinforcing rods for strength, to which a ceramic covering is applied and resistance wire heating elements are spirally wound on the surface of said non-conductive covering and delta connected, and a protective vitreous glaze applied to completely cover said unit and make same completely waterproof so that the unit may be immersed in a tank of liquid as the means of heating said liquid.

It is a further object of this invention to provide a multi-phase electrical immersion heater assembly comprised of a plurality of conductive steel rods insulated from each other but formed into a central core to which a ceramic covering is applied and resistance wire heating elements are spirally wound on the surface of said non-conductive covering and delta connected, and a protective vitreous glaze applied to completely cover said unit and make same completely waterproof so that the unit may be immersed in a tank of liquid as the means of heating said liquid.

Other objects of this invention shall be apparent by reference to the accompanying detailed description and drawings in which FIG. 1 is a side elevational view of a boiler or tank,

FIG. 2 is an end of said boiler or tank,

FIG. 3 is a side view (partially in cross section) of a single phase electric immersion heater assembly shown in a mounted relationship,

FIG. 4 is anend view taken on line 4-4 of FIG. 3,

FIG. 5 is a side view (partially in cross section) of a multi-phase electric immersion heater shown in a mounted relationship,

FIG. 6 is a slightly enlarged side view of the immersion heater of FIG. 5,

FIG. 7 is a schematic illustration of the delta connected multi-phase circuit,

FIG. 8 is an end view (slightly enlarged) taken on line 88 of FIG. 5,

FIG. 9 is an end view (slightly enlarged) taken on line 9-9 of FIG. 5, and

FIG. 10 is a further embodiment of a different design for the central core of the electric immersion heater.

Referring to FIGS. 1 and 2 there is illustrated a typical boiler or tank 10 for water or other fluids. FIG. 1 illustrates an elevational view of a round tank which is one embodiment. Other shapes of tanks may be similarly used. FIG. 2 illustrates an end view showing the boiler or tank end plate 11. With the heating of liquids in tanks of this type, the end plate is generally formed with circular apertures 12 to permit the insertion of electrical immersion heaters 14. The number of apertures 12 may vary according to the demands of the hot water or liquid desired. This invention is primarily concerned with the design and construction of the electrical immersion heater to be installed in the apertures 12.

Referring to FIG. 3 there is illustrated a cross sectional view of a single phase electrical immersion heater to be utilized in conjuction with tank 10 as illustrated in FIGS. land 2. The immersion heater 14 is of an elongated shape and generally circular in form so that the elongated heater 14 may be affixed to the boiler or tank plate 11 and extend through aperture 12 protruding as far as advisable to produce a distributed heating affect on the liquid contents of the boiler or tank. Due to the elongated structure of the heater and due to the non-conducting materials generally utilized, there is a weakness in the structural support and many of the heaters break or are damaged because of rough handling. In this embodiment the immersion heater 14 is provided with two metal reinforcing rods 15 that extend the full length of the heater to provide strength to the elongated non-conducting body 16. The body portion-l6 is generally round in cross section and on opposed sides there are formed deep grooves 16A into which rods 15 are inserted. A non-conductive filler is added to cover each rod in its groove (if the body portion is ceramic, a similar filler of ceramic is used). The finished body with rods 15 inserted will be round in cross section. The ceramic body 16 at one endis, at the same time, formed into an enlarged mounting end which, in this embodiment, appears as a hexagonal shape 17. A further extension of the same ceramic body 16 protrudes from the hexagonal form as a circular extension 18. To insure a perfect seal when the ele-' ment is mounted through an aperture 12, a sealing washer l9, rubber or otherwise, is positioned between the portion 17 and the face of the end plate 11 A clamp 20 in the form of a plate with a central aperture 21 is fitted over the-portion 17. The plate 20 is provided with apertures for a plurality of bolts 22 to pass through. The bolts 22 are mounted through the end plate 11 and welded to the end plate as shown in FIG. 3. Thus with the bolts extending to pass through plate 20, washers and nuts may be affixed to the bolts to draw the end plate 20 into a tight fitting relationship with the ceramic bodyportion l7 retaining it in a squeezed sealed position against the end plate 11. The

, immersion heater 14 also comprises a spirally wound heater resistance wire 24 wound upon the ceramic body 16 as illustrated in FIG. 3. The heater resistance wire 24 is connected at one end to one of the rods 15 and rod 15 in turn is connected to a terminal 25 that extends from the ceramic portion 18 to provide one electrode for the heater. The opposite end of the heater resistance wire 24 is connected at the opposite end of the ceramic body 16 to the end of the other metal reinforcing rod 15 preferably with a drilled insert in the rod and a permanently welded connection. Thus the conductive rod 15 at its opposite end is provided with a welded terminal 26 that also extends from the ceramic body to become the other electrode of the heater element. To insure the protection of the heater element 24 in use, the entire external surface of the ceramic body and resistance wire that is mounted within the tank is glazed with protective vitreous glaze 27. Thus it is apparent that the electric immersion heater as constructed and as illustrated in FIG. 3 will provide a replaceable type mounting for easy removal or insertion of a new element and will provide a tight seal with the end plate of the boiler and will provide a practically indestructible projecting heater within the boiler.

Referring to FIG. there is illustrated a side view partially in cross section of a multi-phase electric immersion heater to be utilized in conjunction with tank of FIGS; 1 and 2. The immersion heater 14A may be affixed to the 'boiler or tank plate 11 and extends through. aperture 12. T oprovide easy installation and removal of the heater, the platell is provided with apertures 12 in anypattern such as that illustrated in FIG. 2. In each aperture 12 a bracket 30 is welded to the end plate 11, the bracket 30 providing a flange 31. Apertures 32 are drilled through flange 31 to permit mounting bolts 33. The immersion heater 14A is provided at one end with an enlarged hexagonal portion 17A. The portion 17A will abut with flange 31 when the immersion heater is inserted through aperture l2.

A sealing washer 34 may be interposed between the flange and portion 17A. A mounting plate 35 is positioned against the outer portion of 17A with the bolts 33 passing through apertures in the plate 35 as illustrated in FIG. 8 and the nuts affixed to the bolts 33 and the plate 35 pulled into a tight fitting relationship with portion 17A to retain the immersion heater in the position as illustrated in FIG. 5 thus providing an easy mounting, a rigid mounting, a sealed mounting and an easily removable mounting.

Referring to FIG. 6, the immersion heater is illustrated slightly larger than shown in FIG. 5 and is comprised of reinforcing rods No. 1, No. 2 and No. 3 in forcing or support for the extended body due to its length to prevent the cracking or breaking of the ceramic portion 16A when supported by the bracket as illustrated in FIG. 5. However rods No. 1, No. 2 and No. 3 are conductive and are therefore used as the electrodes delta connected at one end to a multi-phase heater resistance 24 which is divided in three portions A, B and C. The opposite exposed ends of the reinforcing rods No. 1, No. 2 and No. 3 are connected to the three phase power line 36.

Referring to FIG. 7 we may trace the delta connection of the rods No. 1, No. 2 and No. 3 and the heating element 24. The three phase power line 36 is connected at D, E and F to rods No. 1, No. 2 and No. 3,

that is, D is connected to rod No. 2, E is connected to rod No. 1, F is connected to rod No. 3. The heating element 24 is divided into three portions A, B and C, portion A being connected at one end to rod No. 1 at the far end of the body 16A and to rod No. 2 through the ceramic body as illustrated in FIG. 9. Portion B is connected to rod No. 3 at the outer end of the ceramic body 16A and at the opposite end of portion B it is connected through the ceramic body to rod No. l. Portion C is connected to rods No. 2 and No. 3 being connected atone end to rod No. 2 at the outer end of the body 16A and connected through the ceramic body to rod No. 3 as illustrated in FIG. 9. Thus the multi-phase power supply is delta connectedto the heating element 24. The complete element, that is, the body 16A and the resistance heating elements are coated with a protectective vitreous glaze 27. Thus it is apparent that the electric immersion heater as constructed and as illustrated in FIG. 6 will provide a replaceable type mounting for easy removal or insertion of a new element and will provide a tight seal with the end of a boiler and will provide a practically indestructible projecting immersion heater for the boiler.

A further embodiment of this invention is illustrated in FIG. 10 in which the electrodes No. 1, No. 2 and No. 3 are formed about a Y shaped core of ceramic or insulating material 40 so that the Y shaped core and porspaced relation as illustrated in FIGS. 8 and 9. The rods in this position are completely immersed and covered 8. The rods No. 1, No. 2 and No. 3 are primarily a reintions No. 1, No. 2 and No. 3 when compressed into a tight fitting relationship fonns a perfectly circular core. The core permits the winding of a resistance element such as 24.0f FIG. 6 and is glazed in the same fashion as shown in FIG. 6 with a coating 27.

Although we have shown a typical construction of the electric immersion heater for single phase or multiphase and its mounting and the manner of clamping or retaining theheater in a tight fitting sealed relationship with the boiler end plate, and various forms of electrodes to form a reinforced core, the shape or combination of electrodes, whether single phase or multi-phase may vary without departing from the spirit of this invention and the particular form or pattern of the heating element may vary as long as the reinforced central core is retained to provide the desired indestructible form of heater.

The invention described in detail in the foregoing specification is subject to changes and modifications without departing from the principle and spirit thereof. The terminology used is for purposes of description and not of limitation; the scope of the invention being defined in the claims.

What is Claimed is:

1. An electric multi-phase immersion-type heater comprised of a central core with a plurality of conductive reinforcing elements with a ceramic body bonded to said elements to form the immersion portion of said heater and said ceramic body having one end enlarged to form the exterior end of said body for mounting, an elongated heating resistance wire wound upon the sur face of said ceramic body and divided into a plurality of heating elements, said heating elements delta connected to said conductive reinforcing elements to provide an extended electrode for each heating element, said electrodes extending through said exterior end for connection to a multi-phase power line, said complete external surface of the immersion end of said central core having a fluid-proof non-conductive coating.

2. 'An electric immersion-type heater according to claim 1 in which the central core includes a plurality of spaced conductive re-inforcing rods bonded in their spaced relation to a ceramic body to form a plurality of electrodes that may be delta connected to said heater resistance.

3. An electric immersion type heater according to claim 1 in which the central core includes three spaced conductive reinforcing rods separated by a ceramic non-conductive wall to form a circular core and said circular core covered with a ceramic body.

4. An electric immersion-type heater according to claim 1 in which the exterior enlarged end of said ceramic body is octagonal and a reduced portion of lesser radius protrudes on the exterior end to retain both electrodes.

5. In an immersion-type heater according to claim 4 in which there is a clamping plate with a central aperture to fit over said reduced portion and a plurality of bolts affixed to a boiler, means to clamp said immersion-type heater in a tight fitting relationship to said boiler. 

1. An electric multi-phase immersion-type heater comprised of a central core with a plurality of conductive reinforcing elements with a ceramic body bonded to said elements to form the immersion portion of said heater and said ceramic body having one end enlarged to form the exterior end of said body for mounting, an elongated heating resistance wire wound upon the surface of said ceramic body and divided into a plurality of heating elements, said heating elements delta connected to said conductive reinforcing elements to provide an extended electrode for each heating element, said electrodes extending through said exterior end for connection to a multi-phase power line, said complete external surface of the immersion end of said central core having a fluid-proof non-conductive coating.
 2. An electric immersion-type heater according to claim 1 in which the central core includes a plurality of spaced conductive re-inforcing rods bonded in their spaced relation to a ceramic body to form a plurality of electrodes that may be delta connected to said heater resistance.
 3. An electric immersion type heater according to claim 1 in which the central core includes Three spaced conductive reinforcing rods separated by a ceramic non-conductive wall to form a circular core and said circular core covered with a ceramic body.
 4. An electric immersion-type heater according to claim 1 in which the exterior enlarged end of said ceramic body is octagonal and a reduced portion of lesser radius protrudes on the exterior end to retain both electrodes.
 5. In an immersion-type heater according to claim 4 in which there is a clamping plate with a central aperture to fit over said reduced portion and a plurality of bolts affixed to a boiler, means to clamp said immersion-type heater in a tight fitting relationship to said boiler. 